diff --git a/composer.json b/composer.json
index c849f2e..36163a6 100644
--- a/composer.json
+++ b/composer.json
@@ -12,7 +12,7 @@
         "php": "^8.3",
         "silverstripe/framework": "^6",
         "symfony/event-dispatcher": "^7.0",
-        "psr/event-dispatcher": "^1"
+        "psr/event-dispatcher": "^1.0"
     },
     "require-dev": {
         "phpunit/phpunit": "^11.3",